I'm working on setting up another tank to raise a bunch of Angels and today I noticed these little white bugs on the glass. I took all the fish and plants out of the tank a couple weeks ago and I'm cycling it before I add the fish again. They "creatures" are super-small and white. I noticed a few on the glass. Could they be daphnia? Might they be something harmful to the fish and if so what is the best way to get rid of them? thx.